CCME with Unity 4.x over PSTN

Unanswered Question

I am using CCME 4.0 with a 3725, and have Unity 4.0(4) in a central office. I would like CCME to be integrated with Unity via DID's over the PSTN. Is this possible?

I will have a VPN between the remote site 3725 and the central site, but have been told not to put any voice including voicemail accross the VPN.

Is there a way to do this?


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thisisshanky Wed, 03/07/2007 - 08:58
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Its not wise and also not supported to run voice across vpn's unless you understand that you have no qos guaranteed for voice traffic across the internet.

Certainly CCME integraiton to Unity is supported. Check this link



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Thanks for the response.

I certainly understand the QoS issues over a VPN over the Internet. That is in fact why I'm trying to figure out how to integrate Unity over the PSTN.

Unity will be in another office essentially without a WAN link. I'm just not seeing how to integrate Unity with CCME over the PSTN.



thisisshanky Wed, 03/07/2007 - 09:16
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For this you will need RDNIS (redirecting number) support on your PRI trunks at the main and remote location.

a. Set your gateways to send RDNIS info inbound at HQ and outbound at remote site. You can select this option for an MGCP gateway under callmanager or for a h323 gateway under the pri d-channel interface in the router.

b. At the main site set a 10 digit PSTN number to map to Unity pilot number say 972-111-6000.

c. On the remote site phones, set the call forward destination for busy and no answer to 9 + 1 (if its long distance) + 9721116000 or 9 + 9721116000. (if its local call)

d. When somebody calls a remote site phone, and rings no answer or busy to voicemail, it will place a long distance or local call (as required) to the HQ site. The call will hit unity. Now how does Unity know which mailbox to dump the call into ? Thats where RDNIS is required to be sent from the remote site to the HQ via the PSTN. Only certain telco switches support passing RDNIS information between switches, so you will have to work with your telco to get support for that. From my experience, it works great with primary-ni switches.



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Edit: I posted this based off thinking about Callmanager in my head, so in case of CCME, all you need to do is set the voicemail pilot to 9 + 10 digit number of voicemail pilot and have the ephones call forward to the same pilot as well. RDNIS should take care of the rest.

thisisshanky Wed, 03/07/2007 - 10:37
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One thing i forgot to add is that the setup i explained above will not help with MWI.

To dial MWI for CME phones, you can add a second cluster under your existing Unity integration with Callmanager and specify the CCME router's ip address. In this integration, allocate 2 - 8 ports for dialing mwi only. This mwi traffic will run over vpn, which should be a low overhead traffic. I am not sure if this is a supported configuration by TAC though.


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